title: Osmoregulatory transporter ProP influences colonization of the urinary tract by Escherichia coli.
abstract: Osmoregulatory transporters ProP and ProU mediate the use of betaines as osmoprotectants by Escherichia coli. Glycine betaine and proline betaine are present in mammalian urines. Betaine uptake may therefore facilitate the growth of E. coli in the urinary tract, an environment of fluctuating osmolality. ProP transporter activity was approximately threefold higher in a pyelonephritis isolate, E. coli HU734, than in E. coli K-12. The growth rate of E. coli HU734 in aerated minimal salts medium was reduced twofold by 0.2 M NaCl in the absence and by 0.55 M NaCl in the presence of glycine betaine. Maximal growth rate stimulation was achieved when glycine betaine was added at a concentration as low as 25 microM. Deletion of the proP locus impaired the growth rate of E. coli HU734 in human urine but not in minimal medium supplemented with NaCl (0.4 M), with or without glycine betaine (0.1 mM). The expression of pyelonephritis-associated (P) pili was reduced when E. coli HU734 was cultured in a rich culture medium (LB) of elevated salinity. The proP lesion had no influence on P pilus expression in vitro or on the recovery of bacteria from the kidneys of inoculated mice. However, it did reduce their recovery from the bladders of inoculated mice 100-fold. These data provide the first direct evidence that osmoprotective betaine accumulation and transporter ProP are pertinent to both growth in human urine and colonization of the murine urinary tract by uropathogenic E. coli.
authors.affiliation: Department of Microbiology, University of Guelph, Guelph, ON, Canada N1G 2W1.
authors.forename: Doreen E
authors.initials: DE
authors.lastname: Culham
authors.affiliation: Department of Microbiology, University of Guelph, Guelph, ON, Canada N1G 2W1.
authors.forename: Cheryl
authors.initials: C
authors.lastname: Dalgado
authors.affiliation: Department of Pathobiology, University of Guelph, Guelph, ON, Canada N1G 2W1.|Department of Microbiology, University of Guelph, Guelph, ON, Canada N1G 2W1.
authors.forename: Carlton L
authors.initials: CL
authors.lastname: Gyles
authors.affiliation: Department of Microbiology, University of Guelph, Guelph, ON, Canada N1G 2W1.
authors.forename: Daniel
authors.initials: D
authors.lastname: Mamelak
authors.affiliation: Department of Microbiology, University of Guelph, Guelph, ON, Canada N1G 2W1.
authors.forename: Shawn
authors.initials: S
authors.lastname: MacLellan
authors.affiliation: Department of Microbiology, University of Guelph, Guelph, ON, Canada N1G 2W1.
authors.forename: Janet M
authors.initials: JM
authors.lastname: Wood
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000096:biosynthesis*; D001622:Betaine / Q000494:pharmacology; D002352:Carrier Proteins / Q000096:biosynthesis*; D004926:Escherichia coli / Q000187:drug effects / Q000472:pathogenicity* / Q000502:physiology*; D004927:Escherichia coli Infections / Q000382:microbiology; D029968:Escherichia coli Proteins; D010861:Fimbriae, Bacterial / Q000502:physiology; D005838:Genotype; D006386:Hemagglutination Tests; D006801:Humans; D008322:Mammals; D051379:Mice; D008969:Molecular Sequence Data; D009994:Osmolar Concentration; D010957:Plasmids; D011704:Pyelonephritis / Q000382:microbiology*; D027981:Symporters; D001743:Urinary Bladder / Q000382:microbiology; D014774:Virulence
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; D029968:Escherichia coli Proteins; C079244:ProP protein, E coli; D027981:Symporters; D001622:Betaine